One of these clickety-clickers was Fumie Wakabayashi, a 31-year-old with an infectious laugh and an adventurous spirit. One of a handful of "pin-up Mrs Watanabes" to have achieved national fame - a phenomenon that has enticed more women into the investor fold - Wakabayashi began trading at 20. She wanted to be a nurse but couldn't afford tuition fees after her father's business went bust. Still, she hoped to earn more than the Y900 (£6.90) an hour wage of a waitress or a receptionist.
Wakabayashi's website profile, written in the cutesy style so common in Japan, lists her date of birth as 1977, her blood type as A, her height as 161cm and her weight as 48kg. For a more in-depth insight into her investment strategies, there is always her book, I Like Stocks, or her Nintendo DS investment game. In real life, Wakabayashi is pretty and charming. On a chilly autumn afternoon last year, she gave a women-only lecture for would-be investors in Shibuya, a Tokyo fashion Mecca. "I like the women-only seminars," she says. "They are very serious investors. These days, I think Japanese women are much stronger than men. I don't know how to express it very well, but I think men have become weaker." Wakabayashi says Japan needs to break its cautious mould and learn to embrace more risk. "Now, we can no longer grow as fast as China. So we have to learn to take risks. I want the Japanese to do that more and I think women are taking those chances."
Wakabayashi says she had a more aggressive investment philosophy in her youth, occasionally indulging in "drunk trading" after a few too many cocktails. Like a number of Japanese day traders, she also used to ride waves of volatility, hoping to profit by getting in and out of a trade in the nick of time. These days, she is more of a buy-and-hold investor and says the extreme volatility of the currency markets forced her to exit early before the violent appreciation of the yen last autumn took its toll on those still holding investments abroad, in foreign currencies.